One conventional circuit board assembly includes a circuit board, a circuit board component, and a metallic electromagnetic interference (EMI) cover which fits over the circuit board component and attaches to the circuit board. When the EMI cover is properly in place over the circuit board and the circuit board component, the EMI cover operates as an EMI barrier for the top and sides of the circuit board component. Additionally, a ground plane within the circuit board operates as another EMI barrier for the bottom of the circuit board component. As a result, EMI from the component location can be kept at acceptable levels, and the likelihood of such EMI causing malfunctions is significantly reduced.
The EMI cover typically includes a metallic pan-shaped section, and multiple metallic posts which extend from the periphery of the metallic pan-shaped section. The multiple metallic posts insert into a set of plated through holes (PTHs) of the circuit board which extend around the component mounting location.
In some situations, the manufacturer may solder the posts to the PTHs. To prevent solder from reflowing and possibly forming a solder short between two PTHs, or between a PTH and a neighboring metallic structure (e.g., a mounting pad which connects to the circuit board component), the manufacturer may set various standards or rules such as a requirement that there be a 0.200 inch clearance between the PTHs and the mounting pads, e.g., Surface Mount Technology (SMT) pads.